use strlcpy & strlcat (#74) * refactor checkpubkeyperms() with safe BSD functions fix gcc8 warnings ``` svr-authpubkey.c: In function 'checkpubkeyperms': svr-authpubkey.c:427:2: warning: 'strncat' specified bound 5 equals source length [-Wstringop-overflow=] strncat(filename, "/.ssh", 5); /* strlen("/.ssh") == 5 */ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ svr-authpubkey.c:433:2: warning: 'strncat' specified bound 16 equals source length [-Wstringop-overflow=] strncat(filename, "/authorized_keys", 16); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``` see https://www.sudo.ws/todd/papers/strlcpy.html * restore strlcpy in xstrdup see original https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/xmalloc.c?rev=1.16

#!/usr/bin/perl

# we want to filter every between START_INS and END_INS out and then insert crap from another file (this is fun)

$dst = shift;
$ins = shift;

open(SRC,"<$dst");
open(INS,"<$ins");
open(TMP,">tmp.delme");

$l = 0;
while (<SRC>) {
   if ($_ =~ /START_INS/) {
      print TMP $_;
      $l = 1;
      while (<INS>) {
         print TMP $_;
      }
      close INS;
   } elsif ($_ =~ /END_INS/) {
      print TMP $_;
      $l = 0;
   } elsif ($l == 0) {
      print TMP $_;
   }
}

close TMP;
close SRC;